Just hit a record actual write speed of 2.04GB a second when syncing between two internal SSDs. You generally don't get this kind of speed in the real world (only in tests of brand-new, empty drives). The sync's total was 16.4GB of mixed files (like you would expect a sync to be, and mine hadn't been done in 28 days), and the sync completed in about 40 seconds. The files that it copied at peak speed were large OGG audio files.
My previous record, in similar circumstances, was 1.42GB per second.